Microcrystal line silicon-carbon alloys as anti-reflection window layers in high efficiency thin film silicon solar cells

Microcrystalline silicon-carbide (mu c-SiC:H) films were prepared using hot wire chemical vapor deposition at low substrate temperature. The mu c-SiC:H films were employed as window layers in microcrystalline silicon (mu c-Si:H) solar cells. The short-circuit current density (J(SC)) in these n-side illuminated n-i-p cells increases with increasing the deposition time t(w) of the mu c-SiC: H window layer from 5 min to 60 min. The enhanced J(SC) is attributed to both the high transparency and an anti-reflection effect of the mu c-SiC:H window layer. Using these favourable optical properties of the mu c-SiC:H window layer in mu c-Si: H solar cells, a J(SC) value of 23.8 mA/cm(2) and cell efficiencies above 8.0% were achieved with an absorber layer thickness of 1 mu m and a Ag back reflector. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.